As the title states, any rumors if this could be in works? I'm thinking these two games could use the type of QOL updates that were implemented for System Shock EE.

That would be wonderful indeed !

EA has not been amicable to any overtures by Garriott about any remakes or enhanced editions for ANY Ultima. As he owns the trademark to Lord British and a few other things, I would think that they'd have to get permission from him to reuse those things. Not impossible since he's seemed interested in it, but I wouldn't get your hopes up. The only real hope would be some type of fan made remake or upgrade. Honestly surprised that hasn't even been attempted yet.

Wasn't there a mouselook mod or did I dream that up?

It exists here: https://github.com/JohnGlassmyer/UltimaHacks#ultima-underworld-the-stygian-abyss